SpaceX Tests Falcon 9-R Advanced Reusable Prototype Rocket

Over the past weekend, SpaceX fired up a new version of the Falcon 9, known as the Falcon 9-R, with “R” being for “reusable.” It was the first-ever firing their new advanced prototype rocket. SpaceX told Universe Today the hold-down firing occurred on Saturday, and it lasted for approximately 10 seconds. Elon Musk had tweeted the image above earlier this week, but the company doesn’t normally discuss testing or results, so have not said much about it.

But SpaceX’s communications director Christina Ra did tell us that the Merlin 1D engines used on the test is the same as what’s used on Grasshopper, which is the 10-story Vertical Takeoff Vertical Landing (VTVL) vehicle that SpaceX has designed to test the technologies needed to return a rocket back to Earth intact.

While the Grasshopper uses just one Merlin 1D engine, the Falcon 9-R uses nine, which Musk said via Twitter provides over 1 million pounds of thrust, “enough to lift skyscraper.”

While most rockets are designed to burn up in the atmosphere during reentry, SpaceX’s is hoping their new rocket can return to the launch pad for a vertical landing.

Nancy Atkinson is currently Universe Today's Contributing Editor. Previously she served as UT's Senior Editor and lead writer, and has worked with Astronomy Cast and 365 Days of Astronomy. Nancy is also a NASA/JPL Solar System Ambassador.

Imagine a Falcon 9-R Heavy launch! Two boosters landing simultaneously a couple of hundred meters apart, then the third one coming in a couple of minutes later. Good thing rocket companies don’t sell stocks or a lot of innocent people would get ruined on that day! (Except SpaceX share holders, of course.)

Anyone out there able to postulate how much extra fuel is going to have to be carried in order to bring the booster back? Either they’re going to have to burn the engine an amount proportional to the sum of its empty weight and the return fuel or they’re going to let it fall to some predetermined point and then burn the engine to arrest the fall. Either way that extra fuel has to be accounted for in payload not delivered to orbit and when you come down to it parachutes are lighter and less polluting. Then after you get it back you have to put a whole lot of inspection time into finding what can safely be reused and what can’t.
I’ve got a quarter that says when push comes to shove, it’s not economical to fly it back under power. Takers?

I’ll take it. Let’s worst case a thought experiment and assume pessimistically that the fuel penalty allows only 1/3 the payload to orbit. Under 3% of a rocket’s cost is fuel. After 3 flights you’ve delivered the same payload to orbit, you still have your rocket and the other guy pissed away a rockets cost to orbit the payload. Gets worse for the other guy with more flights. You don’t need that much fuel because you let the rocket fall. It can’t exceed terminal velocity as it approaches the ground at around 250 mph. Brief rocket firing slows to 0 and you land.

Thanks. Made some tries. Too sensitive to parameters I don’t know. Got numbers too high (speed of sound) with small sq meters surface area. I know that SpaceX calculates a couple hundred mph but can’t find a reference to support that.

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SpaceX boosters are super light… fuel tanks with heavy engines at one end, with some remaining fuel.. consider the aerodynamic structural stress of falling sideways.
By landing time, the vehicle is very light.. shouldn’t take much fuel to arrest even a large descent rate..
and there are options for aerodynamic deceleration like drag ‘chutes…

I look forward to seeing the innovative, efficient SpaceX solution.. but since fuel is cheap, and complexity is bad, I wouldn’t be surprised if they use the engines as the only method of velocity control.

SpaceX is not doing this with the F9 1st stage. First stage velocity is similar to Shuttle SRBs. The DO plan to make the re-useable 1st stage more robust with thicker, heavier airframe. Your issue is on point were they to progress to 2nd stage recovery.

“The initial recovery attempts will be from a water landing, so the first-stage booster will, after separation, continue in a ballistic arc and execute a velocity reduction burn in the atmosphere to lessen the impact. Then, right before splashdown of the stage, it’s going to light the engine again. So there will be two burns after stage separation, if things go well,” Musk said.

Air breathing boosters cause drag. Careying your own oxygen is more aerodynamic. Air breathing boosters still need a lot of more development work and most company’s want the government to pay for the development.
The cost of the fuel is $200,000 per Elon Musk. We need the the present day technology, not an air breathing rocket that is a pipe dream for large boosters such as falcon heavy.

That math has been done to death too. While a reusable will lower the payload to LEO from 4 % to 2 % of total, an air breather will lower it to < 0 %. The engines are just too heavy (and expensive, undeveloped, non-reusable et cetera; take your pick).

The one game changer may be the Sabre system, that uses an extensive cooler to drop the heat of the air to what an ordinary jet can handle. But it has yet to prove itself, and is not the type of air breather (such as scram jets) that people have had flying for a few minutes in small scale prototypes.

SpaceX wanted to do this with a reasonable payload, a reasonable development time and a reasonable risk.

What? You’re the internet nobody that thinks he knows better than the actual rocket scientists. You think a parachute never crossed their minds before they started sinking millions into powered descent?

Of couse you’re an aerospace engineer. That is one of the laws of the internet, everybody is an expert in whatever they give opinions on.

The reason I am saying this is you are claiming to know rocket science better than SpaceX. You, random joe on the internet. You know what else is simple fact more efficient? They could just put a little DC electric fan on the side! That would use less fuel than a rocket and less mass than a parachute! But since that doesn’t work, they’re trying something that does.

If your original comment isn’t claiming you know more than SpaceX, then what on earth were you trying to say? Now you’re just backing up so you don’t sound dumb.

I also expected some type of deployed drag devices or ‘chutes.. to reduce the post separation velocity, stabilize the vehicle, reduce the terminal velocity… I also expected some particular configuration and materials to work.
However, SpaceX/Musk tried various options in previous Falcon 1 and Falcon 9 launches without success…. and seem to have given up, and resorted to the engine powered velocity reduction.

the reasons are many. primarily, parachutes are not easily reused. they must be inspected, repaired if necessary, and repacked. the eventual goal for the Falcon 9-R is reuse of a rocket stage within single digit hours. the simplest way to do this is to land the rocket stage without anything that requires labor-intensive inspection, repair, or replacement.

LSAGuy, the math has been done to death. yes, it is possible to do it, and yes, they will take a payload hit. that’s why the tanks for the v1.1 were stretched, to accommodate extra fuel; and more powerful engines were put on it, to provide more power to get more mass to orbit. but in the end, THIS DOES NOT MATTER because they recover 99% of their costs for the mission – the rocket itself – which they can then reuse. it’s a massive savings in cost per mission. it’s hugely economical.

parachutes are antithetical to the idea of rapid reuse of a rocket. parachutes are complex, relatively delicate, need to be inspected, repacked, etc. etc. Musk wants to be able to reuse a rocket within single digit hours.

I would never thrust my satellite to go up on a rocket that landed 9 hours ago and might have a hard bump or a fault during the launch. The launch phase is very traumatic for a rocket. Vibrations, stress, losing air pressure, coldness of space…. Every single component especially electronics are very vulnerable to vibrations.

Be aware that we are comparing apples and pears. Musk’s ultimate goal is massive scale colonization, and a cheap reusable may then demand a few hours turnaround.

Since Musk is comparing with an airplane, the turnaround learning curve is reasonable. For example, the 1st stage reuse that is developed now is not subject to very low temperatures or pressures. Everything else is no different from what an airplane sees – in principle of course.

Meaning the two stages (or 3, in a booster version) may have a different stock for reassembly, with a lot more upper stages. (Here the necessary heat shield will demand more service time if it is ablative and needs redepositing now and then.)

But it is the lower stages that binds up most capital in the form of tank mass and engines.

But there is a difference between claiming that is must be below 10 hours to launch again and a revision that takes 10 hours to check and if no necessary reparation is required it can go on the next launch next week.

Also as a satellite developer, I would not choose to put a very expensive satellite that took years to complete on a cheap rocket. If I choose a low cost rocket then it will be for something inexpensive. Something that can be easily replaced if it blows up.

I am thinking about food supplies, fuel, metal or building materials and spare parts.

It is interesting that they tried to reuse the first stage of the Saturn V Rocket using some para glider.

I would never thrust my satellite to go up on a rocket that landed 9 hours ago and might have a hard bump or a fault during the launch.
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Yet you risk your life and your family in an aircraft that landed minutes ago, flown in hard landings, turbulence, rainstorms?
You think it safer to fly a booster which has NEVER FLOWN.. might have a hundred fatal manufacturing/assembly defects… or one which has flown 50 times successfully.